jens
c98009734c
git-svn-id: http://moon:8086/svn/matlab/trunk@11 801c6759-fa7c-4059-a304-17956f83a07c
37 lines
735 B
Matlab
37 lines
735 B
Matlab
function fdet_eval(f_true, knoise_dB)
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fs = 48000;
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N = 1024;
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phi_true = 1;
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x_true = exp(j*(2*pi*f_true/fs*(0:N-1)'+phi_true)) + sqrt(10^(knoise_dB/10))*randn(N,1);
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% Initial guess
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X = fft(x_true, N);
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[v maxk] = max(abs(X));
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f_est = (maxk-1)*fs/N
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phi_est = angle(x_true(1));
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mu = 1.0;
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for k=1:500
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x_est = exp(-j*(2*pi*f_est/fs*(0:N-1)'+phi_est));
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dmod(k) = sum(x_true.*x_est);
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err(k) = sign(imag(dmod(k)))*(1-real(dmod(k)/abs(dmod(k))))^.5;
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f_est = f_est + mu*err(k);
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f(k) = f_est;
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end;
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f_true = f_true
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f_est = f_est
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close all;
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subplot(3,1,1)
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plot(1:lge(f), 1-real(dmod)./abs(dmod), 1:lge(f), imag(dmod)./abs(dmod)); grid;
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subplot(3,1,2)
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plot(1:lge(f), err, '-*'); grid;
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subplot(3,1,3)
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plot(1:lge(f), f); grid;
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